Ophthalmic solutions are sterile solutions, free or substantially free from foreign particles and/or microorganisms, for instillation into the eye. For certain applications, ophthalmic solutions do not contain medications and are only used as lubricating, tear-replacing, and/or eye wash solutions. Ophthalmic solutions can also contain pharmacologically active ingredients and be used to treat such environment related eye conditions as dry eye, allergies, eye infections such as pink eye, minor eye irritations or conjunctivitis, or structurally related eye conditions such as glaucoma. They can also be used diagnostically by opticians as mydriatic compositions to dilate the pupils of patients during eye examinations.
To avoid introducing infective agents into the eye, it is critical that ophthalmic solutions have and maintain antimicrobial properties by adequately preserving such solutions in their storage containers between uses. Polyquaternium compounds are polycationic polymers that are used as surfactants in the personal care industry. Some have antimicrobial properties, and are useful as preservatives in ophthalmic and/or contact lens solutions.
An issue with the polyquaternium compounds, including the specific compound polyquaternium-42, is their limited ability to provide robust antifungal effectiveness. There is, therefore, a need for compositions useful as ophthalmic solutions having improved antifungal effectiveness, particularly toward the mold Aspergillus brasiliensis. 